PSI - Issue 75

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia (2025) 000 – 000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 75 (2025) 555–563

© 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of Dr Fabien Lefebvre with at least 2 reviewers per paper Experimental results showed that HFMI significantly increased fatigue life in comparison to the untreated reference specimens. Finite Element Analysis (FEA) was used to validate strain measurements in conjunction with strain range drop to aid the testing process. The findings demonstrate the effectiveness of HFMI in enhancing the fatigue life of critical welded bridge details and its potential for broader application in bridge maintenance. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Fatigue Design 2025 organizers Keywords: HFMI; prefatigued specimen; Non-load carrying in-plane gusset plate; Fatigue test; Strain range drop Steel bridges and similar welded structures are highly susceptible to fatigue due to repetitive loading and environmental factors. Addressing fatigue in existing structures is critical for extending their service life and reducing the need for costly replacements. This study investigates the use of High-Frequency Mechanical Impact (HFMI) treatment to extend the fatigue life of welded in plane gusset plates, a detail prone to fatigue and found in many bridges. Welded joints, susceptible to fatigue failure, were tested under pre-fatigue conditions with existing mild notches (0.15 - 0.35 mm) to localize crack initiation and propagation. The study involved HFMI treatment of the notched and pre-fatigued specimens, followed by fatigue testing to evaluate life extension compared to untreated reference specimens. Fatigue Design 2025 (FatDes 2025) Life extension using HFMI of mild notched and prefatigued welded bridge details Martin Edgren 1,2* , Zhelei Jin 1,3 , Mehdi Ghanadi 1 , Zuheir Barsoum 1 1 KTH Royal Institute of Technology, Department of Engineering Mechanics, Division of Material and Structural Mechanics, SE -100 44 Stockholm, Sweden 2 DEKRA Industrial AB, SE-171 26 Solna, Sweden 3 Cargotec Sweden AB Bromma Conquip, Kronborgsgränd 23, SE-164 46 Kista, Sweden Abstract

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Fatigue Design 2025 organizers

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of Dr Fabien Lefebvre with at least 2 reviewers per paper 10.1016/j.prostr.2025.11.056